Research is proposed on sensory, preceptual, and motor functions of children with early brain damage, the methods to be either similar to or identical with those used in studies of adults sustaining injury at maturity. Further controls will consist of developmental studies of the same functions in normal children over a wide age range. Proposed are parallel studies of vision and audition, including detection and fusion threshold, recognition of stimuli under a variety of conditions, and memory. Crossmodal processes will be analyzed in discrimination studies and a prognostic study is to be attempted with children age 3 to 6 suspected of having brain damage. Results should provide information on 1) level of impairment (detection, differentiation, or memory), 2) the modality-specificity of generality of impairment, and 3) the relationship of lateralized deficits to the lateralization of neurological symptoms. Appraisal of results will be in the light of a neurological examination of each child as well as of previous results which suggest the relative sparing of somatosensory processes compared to the deficiencies in motor and more complex functions with early damage.